There are only a few signs you’re still in a city. A spider’s web of telephone lines off in the distance. A tanker truck speeding down an access road to one of the lingering industrial sites that survived the 20th century. A name on the signs that say not to fish, get off the trail, let your dogs bother the birds or go into the fenced area.

The name is misleading. Big Marsh isn’t a marsh. It’s a hemi-marsh, a 50-50 division of emergent vegetation and open water rather than a naturally occurring herbaceous wetland. The name also isn’t the name. It goes by Park No. 564 when it’s at home.

It was an industrial waste dumping ground, once a naturally occurring marsh, but piled deep over decades with runoff, waste and eight feet of steel mill slag. Remediation and reclamation. Now it’s alone and quiet, drops of rain on still, beautiful water.

A massive landfill hill off to the side acts as reminder there’s still work to do.

Away from the hemi, demi, semi-marsh, past a paved walking trail marching by red cargo containers embedded in concrete — some set against the stairway so they could never open even if they wanted to — a sign with a red bike gear replacing the traditional “You Are Here” sign explains what’s going on. It gives the layout of the bike trails the slag heap was turned to. It outlines the skill levels of different routes, the berms and bridges, ramps and rails that will take the BMX set up, down and around.

The lowering your saddles, the full-face helmet, the wearing of shin, knee and elbow armor, body armor, and maybe a neck brace, the last of which “May be considered overkill by some riders but others wouldn’t think of riding without one.”

I look down at the mud below and a little grade school camp field trip training comes back.

That track’s a deer. That track might be a rabbit. That track’s a Cannondale.

No one’s here because it’s November. No one’s here because it’s Sunday. No one’s here because the rain plays pitter-patter on my umbrella.

That feeling I can’t place gets placed. I am alone. Alone on a slag heap turned bike park, by an industrial waste dumping ground turned nature-rich hemi-marsh. Even the rabbits and Cannondales have left this spot to me.

I am in the City of Chicago and I am surrounded by nature. I am in a city and I am breathtakingly alone.